package compat import ( "encoding/json" "fmt" "net/http" "sync" "github.com/containers/podman/v2/libpod" "github.com/containers/podman/v2/libpod/events" "github.com/containers/podman/v2/pkg/api/handlers/utils" "github.com/containers/podman/v2/pkg/domain/entities" "github.com/gorilla/schema" jsoniter "github.com/json-iterator/go" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // filtersFromRequests extracts the "filters" parameter from the specified // http.Request. The parameter can either be a `map[string][]string` as done // in new versions of Docker and libpod, or a `map[string]map[string]bool` as // done in older versions of Docker. We have to do a bit of Yoga to support // both - just as Docker does as well. // // Please refer to https://github.com/containers/podman/issues/6899 for some // background. func filtersFromRequest(r *http.Request) ([]string, error) { var ( compatFilters map[string]map[string]bool filters map[string][]string libpodFilters []string raw []byte ) if _, found := r.URL.Query()["filters"]; found { raw = []byte(r.Form.Get("filters")) } else { return []string{}, nil } // Backwards compat with older versions of Docker. if err := json.Unmarshal(raw, &compatFilters); err == nil { for filterKey, filterMap := range compatFilters { for filterValue, toAdd := range filterMap { if toAdd { libpodFilters = append(libpodFilters, fmt.Sprintf("%s=%s", filterKey, filterValue)) } } } return libpodFilters, nil } if err := json.Unmarshal(raw, &filters); err != nil { return nil, err } for filterKey, filterSlice := range filters { for _, filterValue := range filterSlice { libpodFilters = append(libpodFilters, fmt.Sprintf("%s=%s", filterKey, filterValue)) } } return libpodFilters, nil } // NOTE: this endpoint serves both the docker-compatible one and the new libpod // one. func GetEvents(w http.ResponseWriter, r *http.Request) { var ( fromStart bool decoder = r.Context().Value("decoder").(*schema.Decoder) runtime = r.Context().Value("runtime").(*libpod.Runtime) json = jsoniter.ConfigCompatibleWithStandardLibrary // FIXME: this should happen on the package level ) // NOTE: the "filters" parameter is extracted separately for backwards // compat via `fitlerFromRequest()`. query := struct { Since string `schema:"since"` Until string `schema:"until"` Stream bool `schema:"stream"` }{ Stream: true, } if err := decoder.Decode(&query, r.URL.Query()); err != nil { utils.Error(w, "Failed to parse parameters", http.StatusBadRequest, errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String())) return } if len(query.Since) > 0 || len(query.Until) > 0 { fromStart = true } libpodFilters, err := filtersFromRequest(r) if err != nil { utils.Error(w, "Failed to parse parameters", http.StatusBadRequest, errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String())) return } eventChannel := make(chan *events.Event) errorChannel := make(chan error) // Start reading events. go func() { readOpts := events.ReadOptions{ FromStart: fromStart, Stream: query.Stream, Filters: libpodFilters, EventChannel: eventChannel, Since: query.Since, Until: query.Until, } errorChannel <- runtime.Events(r.Context(), readOpts) }() var coder *jsoniter.Encoder var writeHeader sync.Once for stream := true; stream; stream = query.Stream { select { case err := <-errorChannel: if err != nil { utils.InternalServerError(w, err) return } case evt := <-eventChannel: writeHeader.Do(func() { // Use a sync.Once so that we write the header // only once. w.Header().Set("Content-Type", "application/json") w.WriteHeader(http.StatusOK) if flusher, ok := w.(http.Flusher); ok { flusher.Flush() } coder = json.NewEncoder(w) coder.SetEscapeHTML(true) }) if evt == nil { continue } e := entities.ConvertToEntitiesEvent(*evt) if err := coder.Encode(e); err != nil { logrus.Errorf("unable to write json: %q", err) } if flusher, ok := w.(http.Flusher); ok { flusher.Flush() } } } }